The Cell Culture Core is to serve five main functions: a) as a resource for freshly cultured and immortalized skin cells and skin equivalents; b) as a source for specialized media; c) as a source for antibodies and molecular probes for detection of skin specific markers; d) as a center for information and advice in cell culture techniques; and e) as a center for the development of new techniques applicable to skin research, such as tissue engineering and optimizing procedures for efficient gene delivery into fastidious cells (endothelial cells and melanocytes); these functions will be performed in collaboration with the Scid mouse/Xenograft Core and the Administrative Core of the YSDRC. The core will provide: 1. Primary cultures of normal cells (endothelial cells, melanocytes, keratinocytes, fibroblasts) from healthy donors, as well as malignant, mutant and other abnormal cells from the same patient or different patients; 2. Primary and immortalized mouse cells; 3. Co-cultures, e.g., keratinocytes/melanocytes, fibroblasts/melanocytes, fibroblasts/keratinocytes; endothelial cells/keratinocytes; and various combinations thereof; 4. Skin equivalents; 5. Large volumes of cells for specified procedures such as the construction of cDNA libraries, analysis of genetic alterations, gene expression (mRNA), purification of cytokines, cell surface proteins, etc.; 6. Advice and hands-on training for the growing of cells especially those that have so far proven fastidious, such as CTCL cells and melanocytes from primary melanomas from the radial growth phase. Significance: 1. The core provides cells to individual PI's who lack the expertise or equipment, and to others who wish to save the labor-intensive process. Both groups enjoy the highly economical and cost effectiveness of our services; 2. This core improves the consistency, ease and reproducibility of obtaining skin cells and skin equivalents, and thus enhances the quality of research and reduces the probability of artifacts due to the presence of mycoplasma and/or contaminating cells; 3. The expertise in the central facility provides advice and hands-on help to scientists in growing normal cells that otherwise have been known to be recalcitrant; 4. The core brings together scientists with common interests and enhances interactions that otherwise would not materialize; 5. The core provides primary cultures and special cell types to investigators outside of Yale.